As examples of this type of conveying device drivable by rack gear, conveying devices described in Japanese Published Unexamined Patent Application No. H8-74961 (Patent Literature 1) and Japanese Published Unexamined Patent Application No. 2006-38190 (Patent Literature 2) are known. The configurations described in Patent Literature 1 and Patent Literature 2 are for making a forwardly moving rack gear mesh smoothly with a driving pinion gear pivotally supported at a fixed position, and with the configuration described in Patent Literature 1, a towed hook (rack guide) is mounted to a front of a front end of the rack gear, a driving pinion gear is provided, at a circumference of a rotating body (pinion guide) rotating integrally with the pinion gear, with a drawing-in claw (tooth of the pinion guide) that draws in the rack gear via the towed hook, and the towed hook is engaged with the drawing-in claw in advance of the rack gear. Also, with the configuration described in Patent Literature 2, a front end portion of a rack gear is configured of a separate, vertically swingable member that includes a gear tooth row of fixed length forming the front end portion and a leading tooth of the separate member is used as a towed hook.